A significant mechanical reinforcement of epoxy matrices with carbon
nanotubes (CNTs) requires a very strong covalent interfacial bonding
between the tube and the resin, diglycidylether of bisphenol A (DGEBA).
Using classical molecular dynamics (MD) and density functional theory
(DFT), various methods of improving covalent binding to CNTs are applied
on four major categories: CNT diameters, dopants, defects, and
functional groups. The diameter category includes (n, 0) CNTs with n =
5, 7, 9,11, 13, 15; the dopant category includes B-, N-, and Si-doped
CNTs; the defect category includes CNTs with monovacancies, Stone-Wales,
and more complex nitrogen terminated monovacancies and divacancies; the
functional group category includes CNTs with atomic oxygen, hydroxyl,
amine, carboxyl, and a combination of oxygen and hydroxyl. The
computation of binding energies (BE), affinity indices (AI), and shear
fracture forces on all configurations converged to the conclusion that
smaller tubes, Si-doped CNTs, CNTs functionalized with a combination of
oxygen and hydroxyl, and CNTs with monovacancies show the strongest
indication for mechanical reinforcement in their respective categories.
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